The present invention relates to binding together sheets of paper or other print media. More specifically, the invention relates to binding the sheets using the same imaging material, toner, ink and the like, used to print the text or images on the sheets.
Currently used methods to bind multiple pages together include stapling, clamping, gluing and sewing. Each of these methods add additional xe2x80x9cmixed materialsxe2x80x9d to the final document.
In the case of print jobs including small amounts of paper or other sheet media, the most common method is stapling. Stapling has the advantage that it is useful for short runs in that elaborate sewing or other assembly equipment is not required. A disadvantage of stapling is that stapling requires one or more relatively complex and expensive stapling mechanisms. Another disadvantage is that stapled papers have poor stacking characteristics. In the case of documents which are produced by the use of laser printers, any additional procedures involve the use of additional equipment, either within the printer or external to the printer. That means that the ability of providing office printers which are capable of providing assembling booklets or other multi-page brochures is limited.
It would be desired to provide a method or apparatus for assembling multiple sheets of paper or other sheet media which does not require any additional material to fix the sheet media. It is desired to avoid items such as staples, glue, or thread, and more particularly it is desired to avoid the cost and handling of such additional materials. It is further desired that a laser printer or similar piece of equipment be provided with an ability to assemble print jobs in bound format, without the requirement that the printing equipment be made substantially more complicated or less economical. It is desired to provide a simplified automatic paper binding device for such a printer.
Another disadvantage of prior art paper binding equipment is the tendency of pages becoming damaged upon separation. In some cases, staples and other binding devices can be carefully removed and then carefully re-inserted. While individuals disassembling and reassembling original copies are often willing to exert more effort in the reassembly than would be required for originally binding the document, it is often the case that individuals will not wish to engage in activities which require precise mechanical skills just to re-bind a document. Therefore, a re-bound document will often have a tattered appearance.
Often a document is produced and assembled as a bound document, only to be unbound for further processing or duplication. In such a case, it is desired to have a binding mechanism which permits the document to be provided in bound form, but which also permits the document to be disassembled for further handling. Thus, if the document is to be stapled, the stapling need occur only after the completion of paper handling, even if the document is initially delivered in a bound form. In the prior art, this was accomplished by either paper clipping the document, and then stapling or attaching a binder to the document, or by initially binding the document on a more permanent basis, such as by stapling, followed by removing the staple, followed by re-binding the document. Needless to say, the binding and unbinding of the document is complicated and disadvantageous.
In producing a document, often pre-processing and post-processing steps are required. In the case of an individual letter, this includes signing and folding the letter, followed by inserting the letter into an envelope, sealing the envelope and applying postage. In the case of mass mailings, it is often not necessary to sign the letter, but the other steps must be performed, such as sorting by address.
Arrangements to provide documents in letter form, along with folding, sealing and franking are referred to as xe2x80x9cmailing systems.xe2x80x9d Mailing systems are used for pre-printed forms, but often individualized documents such as bills require that primary documents to be mailed be individually produced and incorporated into the mailing system.
In some cases, bound stacks of paper are intended to be unbound in use. This is the case with writing pads or tablets in which the sheets are removed at a glue line or perforation. If pre-printed forms are desired in this format, setup costs are significant. Therefore, large print runs are required to economically provide such forms in tablet format. It would be desirable to provide an ability to economically print forms in small runs.
The attachment of multiple larger sheets to form booklets is well-known, and the bookbinding art even has conventional numbers of pages in which smaller sections, called xe2x80x9csignaturesxe2x80x9d or xe2x80x9cunits,xe2x80x9d containing 16, 32, or 64 pages, are assembled for purposes of printing and bookbinding. The present invention relates to a technique useful for creating signatures as well as for smaller signatures and for pamphlets.
One problem of binding documents is the fact that the bound document is composed of mixed materials. When the document is to be recycled, the mixed materials either degrade the recyclability of the document or require that recycling facilities be able to separate the mixed materials. Thus, plastic, glue, tape and staples must be addressed as additional materials besides the paper and ink which forms the basis of the document. The use of mixed materials thereby creates an economic cost which either appears in the cost of raw materials and waste. In some cases, these costs are transferred to the user through sanctions commensurate with the economic costs involved in the use of materials which are more difficult to recycle.
As a result, it would be advantageous to provide a document product which, in bound form, consists of the paper and ink that forms the basis for the paper product, and in which the binding process does not add additional types of material to the product. By reducing the mix of materials, recycling is simplified.
In binding of documents, it would be desirable to vary parameters or material properties to allow adjustments in holding force used to adhere the pages together. This would facilitate adjusting the binding of the pages between permanent fixation to light or temporary fixation. Presently this is accomplished by paper clipping the sheets together or by carefully removing and replacing staples.
One of the problems with post-printing processing is that the user must wait until completion of the process. It is therefore desired that a post-printing binding process not consume significantly more time than the printing of the document.
The present invention is directed to new techniques and devices for printing and binding sheet media using imaging material as the binder and the documents produced using these new techniques. In general, patterns of imaging material are printed in selected binding regions on one or both of the opposing surfaces to bind sheets together. The binding regions typically may be any shape and number adequate to bind the sheets permanently or temporarily, as necessary or desired, and may be printed at the same time the image of the page is printed. The imaging material in the binding regions is re-activated after the page is printed by any combination of exposure to conducted or radiated heat, pressure, electric or magnetic fields chemical, ultrasound or by any other suitable means.
In one embodiment of the invention, imaging material is applied to facing sides of the sheets to bind them together. Unlike conventional methods where a the imaging material is more dense in the binding region on each sheet, in this embodiment of the invention the imaging material can be applied to the same thickness in the binding region and in the print pattern. In this first embodiment, imaging material is applied in a pattern of a desired print image and to a binding region on each sheet. The binding region is aligned with and faces a binding region on an adjacent sheet when the sheets are assembled for binding. The imaging material is activated. Where laser toner is used as the imaging material, the activation process is called fixing or fusing the toner. Then, the sheets are assembled for binding and the imaging material in the binding region re-activated (re-fused if laser toner is used as the imaging material) to bind the sheets.
In a second embodiment, the imaging material in the binding region is reactivated as each sheet or a group of sheets comes out of the printer. This embodiment includes the steps of (1) applying imaging material in a pattern of a desired print image on each sheet, (2) applying imaging material to a binding region on each sheet, (3) activating the imaging material, (4) assembling two or more sheets for binding, (5) re-activating imaging material in the binding region to bind the assembled sheets, (6) assembling at least one additional sheet with the sheets previously bound, (7) re-activating imaging material in the binding region to bind the additional sheet(s), and (8) repeating the steps of assembling and re-activating until all sheets are bound.
In a third embodiment, the imaging material is used to bind the sheets in a booklet along a fold line. In this third embodiment of the invention, imaging material is applied to a binding region along the fold line of each sheet. The sheets are then assembled for binding along the fold line and the imaging material in the binding region is re-activated to bind the sheets into a booklet.
Variation of parameters or material properties of the printing material can be used to allow adjustments in holding force used to adhere the pages together. Therefore, it is possible to vary the binding of the pages between strong or permanent fixation to light or temporary fixation. The ability to vary the binding force allows a document to be optimally temporarily assembled and then later disassembled without significantly damaging the sheets.
Image, as used herein, means a visually perceptible text or graphic marking and photographic imaging, including both color and monochromatic presentations. xe2x80x9cImaging materialxe2x80x9d means printing material deposited on a sheet of paper or other sheet media and includes laser toner, printing ink, or any other type of toner or material which is used for producing an image on a document. It is, of course, possible that a variation in the material be established in suitable circumstances so that the pigmentation of the imaging material is less noticeable. Such imaging material is deposited upon xe2x80x9csheet mediaxe2x80x9d which may include paper or other materials which are used for receiving a printed image. Typically, printed documents include at least sheet media and printing material.